This invention relates to improvements in means and methods for fabricating annular or tubular fittings, sleeve-type connectors and fasteners, especially those having the character of nuts. Such devices are often characterized by the need for having specially configured portions of their exterior surface as well as surface threading. This is particularly true of nuts which require a plurality of circumferentially spaced flats on their outer peripheral surface to facilitate their manipulation to obtain their secure application as well as to provide a base facilitating their removal and/or disengagement from the elements to which they apply. Since the invention is particularly advantageous in application to the production of nut type connectors and fasteners, the invention will be herein illustrated with reference to an embodiment for use in making cap nuts.
Nuts heretofore have generally been fabricated from bar stock in a procedure which has frequently produced an end product less than satisfactory as to its dimension and form. More than this, its fabrication has often demanded not only a series of time consuming and costly difficult and power-consuming machining steps but the use of expensive stock, such as hex and other specially shaped bar stock.
The present invention essentially eliminates the above mentioned problems and difficulties which have for many, many years plagued those engaged in the fabrication and use of nut type connectors. It affords, moreover, a concept of fabrication and apparatus to achieve the same which not only features the use of comparatively inexpensive tubing as the basic stock from which nuts are formed but also provides for a simple precision forming, shaving and tapping of tubing by means of which a large variety of nuts may be produced relatively inexpensively in an extremely short period of time.
In general and specifically the present invention enables a machine for and process of fabrication of annular or tubular fasteners and connector devices having the characteristics of nuts which are more economical to employ, more efficient and satisfactory in use, and adaptable to a wide variety of applications. Most importantly, the invention provides that the end products resulting can be easily and more precisely controlled as to their desired dimension and configuration.
As far as the inventors are aware, there have been previous efforts to use tubular stock for the fabrication of nuts but without particular success. The concept involved in such efforts required that tubing be squeezed to produce a hex or comparable shape on its outer peripheral surface. The efforts apparently failed because the result of the squeezing was to produce an out-of-round condition of the inner diameter of the tubing, obviously negating its use for the end product desired.